MR8740、MR8741_user_manual_eng_20191016H.pdf - 第206页
8.3 Triggering by Analog Signals 194 3. V oltage Sag T rigger ( only) _____________________________ Triggering occurs when the voltage peak drops below a preset level for more than half a cycle. The allowa ble time axis …
8.3 Triggering by Analog Signals
193
7
Chapter 8 Trigger Settings
8
1. Level Trigger ________________________________________________
A trigger is applied when an input signal crosses the specified trigger level
(threshold voltage).
2. In-Window Trigger, Out-of-Window Trigger _______________________
Upper and lower limit values are set for the trigger level, and triggering occurs
when the input signal enters this range (In) or leaves this range (Out).
Trigger Level
Input Waveform
Trigger Slope:
[
]
T
T
[ ]
In this manual, indicates a "trigger point", as the time at which a trigger is
applied.
T
Type Parameters
[Level]
[L] (Level)
Sets the level (voltage value) for the trigger. (The setting
can be made in 1/50 increments.)
[S] (Slope)
Determines whether triggering occurs when the signal
crosses the threshold (trigger level) on the upslope (rising
edge) or on the downslope (falling edge). With the [ ] set-
ting, triggering occurs in either direction.) ( )
[Event]
The number of signal rising edge (or falling edge) events is
counted, and triggering occurs when the Event number set
here is exceeded. (1 to 4000)
[F] (Filter)
Triggering occurs when the trigger criteria are met within
the specified filter width. This is useful to prevent spurious
triggering due to noise. ( : Off, 0.1 - 10 div)
Upper Threshold
Lower Threshold
T
T
Upper Threshold
Lower Threshold
T
T
(In)
(Out)
Type Parameters
[In]
or
[Out]
[Lower]
Set the lower limit value.
(The setting can be made in 1/50 increments.)
[Upper]
Set the upper limit value.
(The setting can be made in 1/50 increments.)
[F] (Filter)
Triggering occurs when the trigger criteria are met within
the specified filter width. This is useful to prevent spurious
triggering due to noise. ( : Off, 0.1 - 10 div)
8.3 Triggering by Analog Signals
194
3. Voltage Sag Trigger ( only) _____________________________
Triggering occurs when the voltage peak drops below a preset level for more
than half a cycle. The allowable time axis range is 20 s - 50 ms/div.
4. In-Period Trigger, Out-of-Period Trigger__________________________
The rising edge and falling edge cycle of the reference voltage is measured, and
triggering occurs when the cycle enters the preset range (In) or leaves the preset
range (Out).
See: "Description" (p.196)
*1: Changes in sync with the time axis range.
Type Parameters
[VDrop]
[L] (Level) Sets the level (voltage value) for the trigger. (The setting
can be made in 1/50 increments.)
[f=] (Frequency) Select 50 or 60 Hz.
RMS:
(actual value)
It is an aim of the actual value. Changes in sync with the
level setting.
T
1/2 Period
Trigger Level
Type Parameters
[Per.I]
or
[Per.O]
[L] (Level) Sets the level (voltage value) for the trigger. (The setting
can be made in 1/50 increments.)
[S] (Slope) Determines whether triggering occurs when the signal
crosses the threshold (trigger level) on the upslope (ris-
ing edge) or on the downslope (falling edge). ()
[P]
(Period lower
limit)
*1
Available settings are 0 and more than 5 times the sam-
pling frequency. Settings higher than the upper limit val-
ue are not accepted. (When the setting is 0, the lower
limit is disregarded, and triggering occurs only on the
upper limit.)
[]
(Period upper
limit)
*1
The setting range extends to 20,000 times the sampling
frequency. Lower settings than the lower limit value are
not accepted.
[F] (Filter) Triggering occurs when the trigger criteria are met with-
in the specified filter width. This is useful to prevent spu-
rious triggering due to noise. ( : Off, 0.1 -
10 div)
Within Period
Range
Out of Period Range
T
Reference
Voltage Level
Period Upper Limit
Period Upper Threshold
Period Lower Limit
About the Trigger Point
The trigger point occurs one sam-
ple after the criterion is met.
8.3 Triggering by Analog Signals
195
7
Chapter 8 Trigger Settings
8
5. Glitch Trigger( only) ___________________________________
Triggering occurs when the input signal crosses the trigger level (threshold volt-
age) if its pulse width is shorter than the specified width.
Suppressing Noise Effect
Noise near the trigger level can erroneously increment the event count. Set the trig-
ger filter to avoid such effects.
Type Parameters
[Grit.]
[L] (Level) Sets the level (voltage value) for the trigger. (The setting
can be made in 1/50 increments.)
[S] (Slope) Determines whether triggering occurs when the signal
crosses the threshold (trigger level) on the upslope (rising
edge) or on the downslope (falling edge). ()
[Event]
The number of signal rising edge (or falling edge) events
is counted, and triggering occurs when the Event number
set here is exceeded. (1 to 4000)
[Width] Sets the pulse width (time) that is used to determine a
glitch. Triggering occurs when the width is lower than this
value. (The available setting range depends on the sam-
pling frequency. Lower limit: sampling frequency x 2, up-
per limit: sampling frequency x 4000)
Glitch Width
Trigger Level
Input Waveform
Trigger Slope: [
]
T
When Using Noisy Signals for Triggering
Method 1: Enable the trigger filter
By setting the filter width to prevent triggering on noise, triggering occurs only
when the trigger criteria continue to be met for at least the specified width
(interval).
Method 2: Setting an Event Count
If triggering occurs too frequently, an event count can be specified so that a
trigger is accepted only after the specified number of trigger events has
occurred.
Trigger Level
The noise does not cause triggering.
T
Trigger Point
Filter Width
2.5 V
5 V
0 V
Trigger Level
T
1234
Example: When the event count is set to [4] (Slope: )
Event Count